[J3] HPC rant against the standard committees

[Bill Long]

I do know these guys.  I should read their book.

> On Apr 20, 2018, at 4:36 AM, Anton Shterenlikht via J3 <j3 at mailman.j3-fortran.org> wrote:
> 
> "Unfortunately, array syntax is still with us and while many
> programmers feel it is easier to use than the standard old
> Fortran DO loop, the real issue is that most Fortran compilers
> cannot generate good cache efficient code from a series
> of array assignment statements.”


Interesting considering that the compiler they most often use converts “array syntax” into DO loops before optimization since that is what the compiler was taught to vectorize.  And multiple consecutive array statements with the same shape are “fused” exactly so that the compiler can generate good cache use. This sort of optimization is pretty low hanging fruit.   I guess “most Fortran compilers” refers to other compilers.   

Cheers,
Bill


Bill Long                                                                       longb at cray.com
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